Git rebase使用詳解
git rebase能夠?qū)⒎植娴姆种е匦潞喜ⅲ皩?xiě)過(guò)一篇文章介紹它的原理，下面主要介紹它的兩個(gè)使用場(chǎng)景：
場(chǎng)景一：本地與遠(yuǎn)端同一分支提交歷史不一致
方式一
多個(gè)人在同一個(gè)分支上協(xié)作時(shí)，出現(xiàn)沖突是很正常的，比如現(xiàn)在有一個(gè)項(xiàng)目由我和A一同開(kāi)發(fā)。
我在修復(fù)了一個(gè)bug以后準(zhǔn)備提交
HowiedeiMac:ganlin howie$ git add models/paper.goHowiedeiMac:ganlin howie$ git commit -m 'fix a bug'[master 8b76654] fix a bug1 file changed, 3 insertions(+), 3 deletions(-)
現(xiàn)在準(zhǔn)備推送到遠(yuǎn)端
HowiedeiMac:ganlin howie$ git push origin masterTo https://gitee.com/greenhn/ganlin.git! [rejected] master -> master (fetch first)error: failed to push some refs to 'https://gitee.com/greenhn/ganlin.git'hint: Updates were rejected because the remote contains work that you dohint: not have locally. This is usually caused by another repository pushinghint: to the same ref. You may want to first integrate the remote changeshint: (e.g., 'git pull ...') before pushing again.hint: See the 'Note about fast-forwards' in 'git push --help' for details.
push失敗了，說(shuō)明A在我之前已經(jīng)提交了，我本地master分支的提交歷史已經(jīng)落后遠(yuǎn)端了，需要先pull一下，與遠(yuǎn)端同步后才能push
HowiedeiMac:ganlin howie$ git pullremote: Enumerating objects: 14, done.remote: Counting objects: 100% (14/14), done.remote: Compressing objects: 100% (8/8), done.remote: Total 8 (delta 6), reused 0 (delta 0)Unpacking objects: 100% (8/8), done.From https://gitee.com/greenhn/ganlinmaster -> origin/masterMerge made by the 'recursive' strategy.| 14 +++++++++++---| 8 ++++----| 3 +++| 3 +++4 files changed, 21 insertions(+), 7 deletions(-)
pull成功，現(xiàn)在使用git log看下一提交歷史：
HowiedeiMac:ganlin howie$ git log --oneline --graph* f63ecbf (HEAD -> master) Merge branch 'master' of https://gitee.com/greenhn/ganlin|\| * b91f711 (origin/master, origin/HEAD) 修正bug，優(yōu)化內(nèi)置通道配置* | 8b76654 fix a bug|/* a1bc60a 完善日?qǐng)?bào)接口* 9f73b5e 增加內(nèi)置通道設(shè)置功能* a0d464e ...
竟然分叉了！由于我本地master的提交歷史和遠(yuǎn)端的master分支的提交歷史不一致，所以git為我進(jìn)行了自動(dòng)合并，然后生成了一個(gè)新的提交歷史（f63ecbf Merge branch 'master' of）
對(duì)于部分強(qiáng)迫癥來(lái)說(shuō)這個(gè)不能接受的，不想看到分叉。
這個(gè)時(shí)候用git rebase就可以解決
HowiedeiMac:ganlin howie$ git rebaseFirst, rewinding head to replay your work on top of it...Applying: fix a bug
現(xiàn)在再查看一下提交歷史：
HowiedeiMac:ganlin howie$ git log --oneline --graph* 2e2b995 (HEAD -> master) fix a bug* b91f711 (origin/master, origin/HEAD) 修正bug，優(yōu)化內(nèi)置通道配置* a1bc60a 完善日?qǐng)?bào)接口* 9f73b5e 增加內(nèi)置通道設(shè)置功能* a0d464e ...
完美解決，現(xiàn)在再push推送到遠(yuǎn)端：
HowiedeiMac:ganlin howie$ git push origin masterEnumerating objects: 7, done.Counting objects: 100% (7/7), done.Delta compression using up to 4 threadsCompressing objects: 100% (4/4), done.Writing objects: 100% (4/4), 394 bytes | 394.00 KiB/s, done.Total 4 (delta 3), reused 0 (delta 0)remote: Powered By Gitee.comTo https://gitee.com/greenhn/ganlin.gitmaster -> master
再次查看提交歷史
HowiedeiMac:ganlin howie$ git lg --oneline --graph* 2e2b995 (HEAD -> master, origin/master, origin/HEAD) fix a bug* b91f711 修正bug，優(yōu)化內(nèi)置通道配置* a1bc60a 完善日?qǐng)?bào)接口* 9f73b5e 增加內(nèi)置通道設(shè)置功能* a0d464e ...
現(xiàn)在遠(yuǎn)端master，遠(yuǎn)端head，本地master全部統(tǒng)一，問(wèn)題解決。
方式二
直接執(zhí)行：git pull --rebase
效果與上面是一致的，也是最近才發(fā)現(xiàn)，推薦使用
場(chǎng)景二：不同分支之間的合并
由于老板突發(fā)奇想，要求開(kāi)發(fā)一個(gè)新的功能。
先創(chuàng)建一個(gè)分支用于開(kāi)發(fā)新功能：
git checkout -b feature
HowiedeiMac:hello howie$ git checkout -b featureSwitched to a new branch 'feature'HowiedeiMac:hello howie$ git branchfeaturemaster
接下來(lái)修改newFunc.go，增加新的功能,并且保存提交
vim newFunc.gogit add newFunc.gogit commit -m 'add new func'
現(xiàn)在查看一下提交
HowiedeiMac:hello howie$ git log --oneline --graph* 4f58ab8 (HEAD -> feature) add new func* 94c134b (master) init baseHowiedeiMac:hello howie$ git branch* featuremaster
現(xiàn)在新功能開(kāi)發(fā)完畢，需要將它合并的主分支中。
先嘗試通過(guò)merge合并：
首先切換到master分支
git checkout master
HowiedeiMac:hello howie$ git checkout masterSwitched to branch 'master'Your branch is up to date with 'origin/master'.
直接合并feature分支
git merge feature
HowiedeiMac:hello howie$ git merge featureAuto-merging newFunc.goCONFLICT (content): Merge conflict in newFunc.goAutomatic merge failed; fix conflicts and then commit the result.
竟然失敗了，說(shuō)明我兩個(gè)分支之前的版本已經(jīng)不同步了，需要手動(dòng)合并沖突，再提交：
先查看沖突文件：git status
HowiedeiMac:hello howie$ git statusOn branch masterYour branch is ahead of 'origin/master' by 7 commits.(use "git push" to publish your local commits)You have unmerged paths.(fix conflicts and run "git commit")(use "git merge --abort" to abort the merge)Unmerged paths:(use "git add <file>..." to mark resolution)both modified: newFunc.go
打開(kāi)文件，進(jìn)行修改
原文件：
func NewFunc() {<<<<<<< HEAD=======fmt.Println("add new func")>>>>>>> feature}
修改后：
func NewFunc() {fmt.Println("add new func")}
現(xiàn)在通過(guò)add添加，然后commit提交
HowiedeiMac:hello howie$ git add newFunc.goHowiedeiMac:hello howie$ git commit -m 'merge master and feature'[master 562ec58] merge master and feature
現(xiàn)在在查看一下分支提交歷史：
HowiedeiMac:hello howie$ git log --oneline --graph* 562ec58 (HEAD -> master) merge master and feature|\| * 4f58ab8 (feature) add new func* | 0e80f97 do something|/* 94c134b init base
雖然合并成功，但是Master已經(jīng)保存了合并歷史，出現(xiàn)開(kāi)叉了！對(duì)于強(qiáng)迫癥患者來(lái)說(shuō)肯定是不能接受的。
通過(guò)rebase合并分支：
現(xiàn)在將版本退回到合并前,也就是回退一個(gè)版本
git reset --hard head^
HowiedeiMac:hello howie$ git reset --hard head^HEAD is now at 0e80f97 do somethingHowiedeiMac:hello howie$ git log --oneline --graph* 0e80f97 (HEAD -> master) do something* 94c134b init base
退回去了，現(xiàn)在是位于master分支的init base提交這里。
先切換回feature分支：
HowiedeiMac:hello howie$ git checkout featureSwitched to branch 'feature'
在feature分支上執(zhí)行: git rebase master
這句命令的意識(shí)是：以master為基礎(chǔ)，將feature分支上的修改增加到master分支上，并生成新的版本。
HowiedeiMac:hello howie$ git rebase masterFirst, rewinding head to replay your work on top of it...Applying: add new funcUsing index info to reconstruct a base tree...M newFunc.goFalling back to patching base and 3-way merge...Auto-merging newFunc.goCONFLICT (content): Merge conflict in newFunc.goerror: Failed to merge in the changes.Patch failed at 0001 add new funchint: Use 'git am --show-current-patch' to see the failed patchResolve all conflicts manually, mark them as resolved with"git add/rm <conflicted_files>", then run "git rebase --continue".You can instead skip this commit: run "git rebase --skip".To abort and get back to the state before "git rebase", run "git rebase --abort".
失敗了，原因很簡(jiǎn)單，兩個(gè)分支修改個(gè)同一個(gè)文件，產(chǎn)生了沖突。所以先需要解決沖突：
打開(kāi)沖突的文件，解決沖突
原文件：
func NewFunc() {<<<<<<< HEAD=======fmt.Println("add new func")>>>>>>> add new func}
修改后：
func NewFunc() {fmt.Println("add new func")}
現(xiàn)在通過(guò)add添加
HowiedeiMac:hello howie$ git add newFunc.go現(xiàn)在是重點(diǎn)，之前的rebase其實(shí)只是完成了一半，由于出現(xiàn)沖突而終止，現(xiàn)在沖突解決，可以通過(guò)git rebase —continue繼續(xù)完成之前的rebase操作。
HowiedeiMac:hello howie$ git rebase --continueApplying: add new func
rebase完成，再查看一下提交歷史：
HowiedeiMac:hello howie$ git log --oneline --graph* b2593e6 (HEAD -> feature) add new func* 0e80f97 (master) do something* 94c134b init base
提交記錄已經(jīng)是一條完美的直線。現(xiàn)在切換到主分支master，將feather分支上的提交合并過(guò)來(lái)。
git checkout mastergit merge feature
HowiedeiMac:hello howie$ git checkout masterSwitched to branch 'master'Your branch is ahead of 'origin/master' by 7 commits.(use "git push" to publish your local commits)HowiedeiMac:hello howie$ git merge featureUpdating 0e80f97..b2593e6Fast-forwardnewFunc.go | 1 +1 file changed, 1 insertion(+)
再次查看一下提交歷史：
HowiedeiMac:hello howie$ git log --oneline --graph* b2593e6 (HEAD -> master, feature) add new func* 0e80f97 do something* 94c134b init base
問(wèn)題解決，master上也是一條直線了。
最后收個(gè)尾，刪除掉feature分支：
HowiedeiMac:hello howie$ git branch -d featureDeleted branch feature (was b2593e6).